1. Field of the Invention
The present invention relates in general to manufacturing lines for manufacturing heat exchangers used in automotive air conditioners, each heat exchanger comprising a plurality of parallel flat heat extending tubes arranged to constitute a rectangular mass, a plurality of outer fins alternatively arranged in the mass of the flat heat extending tubes and two header pipes connected to opposed sides of the mass. More particularly, the present invention relates to the heat exchanger manufacturing lines of a type which comprises a header pipe producing device which produces the header pipes by pressing or curling flat metal plates, a flat tube producing device which produces the flat heat exchanging tubes each including an elongate flat metal tube and an elongate inner metal fin installed in the flat tube, an outer fin producing device which produces the outer fins by corrugating an elongate metal plate, and assembling devices which produce the heat exchangers one after another by assembling the header pipes, the elongate flat tubes and the outer fins. More specifically, the present invention is concerned with workpiece handling devices arranged in the heat exchanger manufacturing line, which handle the flat heat exchanging tubes for assisting the operation of the above-mentioned producing and assembling devices.
2. Description of the Prior Art
In the heat exchanger manufacturing lines of the above-mentioned type, there are employed various handling devices for handling workpieces or flat tubes. One of the handling devices is a workpiece posture changing device which is arranged between first and second conveyers to change the posture of a workpiece, which has just released from the first conveyer, for properly putting it on the second conveyer. Another handling device is a workpiece bundling device which is arranged at a terminal position of a conveyer for bundling a certain number of the workpieces which have been conveyed thereto by the conveyer. However, some of the workpiece posture changing devices and the workpiece bundling devices hitherto proposed have failed to provide users with a satisfaction due to their insufficient handling efficiency.